product_list = [
    ("华为P30",4000),
    ("Mac pro",16000),
    ("Milk tea",15),
    ("crabs",88),
    ("bike",400),
    ("watch",40000),
    ("head first python",128),
    ("book",40),
]
shopping_car = []
Alipay = input("请输入支付宝余额：")
if Alipay.isdigit():
    Alipay = int(Alipay)
    while True:
        for item in product_list:
            print(product_list.index(item),item)
        choice = input("请选择你要购买的商品序号：")
        if choice.isdigit():
            choice = int(choice)
            if choice >= 0 and choice < 8:
                if Alipay >= product_list[choice][1]:
                    Alipay = Alipay - product_list[choice][1]
                    shopping_car.append(product_list[choice])
                    print("把商品%s添加到购物车，支付宝余额是%s:"%(product_list[choice][0],Alipay))
                else:
                    print("没钱了还买还买，看看有啥买得起的吧")
            else:
                print("请你睁大眼睛看看你选这玩意在不在这个列表然后再选一个")
        elif choice =="q":
            print("----购物车清单----")
            for item in shopping_car:
                print("你的支付宝余额%s:"%Alipay)
                break
        else:
            print("按q退出程序")
else:
    print("请输入数字金额")
